Chapter 14 Equilibrium #2

Sulfur dioxide combines with O₂ in the presence of a catalyst as represented by the equation

2SO₂(g) + O₂(g) ↔2SO₃(g)

Suppose 0.10 mol of SO₂ and 0.10 mol of O₂ are added to a 1-L vessel. At equilibrium, which of the following conditions must be true?

• [O₂] = 2[SO₃]

• [SO₂] > [O₂]

• [SO₂ < [O₂]

• [SO₂] = [O₂]

The following reaction is investigated (assume an ideal gas mixture):

2N₂O(g) + N₂H₄(g) ↔ 3N₂(g) + 2H₂O(g)

Initially there are 0.100 mol of N₂O and 0.25 mol of N₂H₄, in a 10.0-L container. If there are 0.059 mol of N₂O at equilibrium, how many moles of N₂ are present at equilibrium?

• 0.021

• 0.042

• 0.062

• 0.12

Which expression correctly describes the equilibrium constant K_c for the following reaction?

2C₂H₂(g) + 5O₂(g) ↔4CO₂(g) + 2H₂O(g)

• Kc = [CO₂][H₂O] / [C₂H₂][O₂]

• c = [CO₂]² [H₂O]⁵ / [C₂H₂]² [O₂]

• c = [CO₂]⁴ [H₂O]² / [C₂H₂]²[O₂]⁵

• c = [CO₂] + [H₂O] / [C₂H₂] + [O₂]

A sample of ammonia gas was allowed to come to equilibrium at 400 K.

2NH₃(g) ↔ N₂(g) + 3H₂(g)

At equilibrium, it was found that the concentration of H₂ was 0.0551 M, the concentration of N₂ was 0.0183 M, and the concentration of NH₃ was 0.383 M. What is K_c for this equilibrium?

• 3.97x10^-3

• 1.58x10^-5

• 2.10x10^-5

• 2.40x10^-3

In an experiment, 0.30 mol H₂ and 0.30 mol I₂ are initially mixed in a 1.00-L container, and the reaction forms HI. If K_c = 49. for this reaction, what is the equilibrium concentration of HI?

I₂(g) + H₂(g) ↔2HI(g)

• 0.58 M

• 0.53 M

• 0.47 M

• 0.040 M

At 550 K, Kc = 7.7 × 10² for the following equilibrium.

SO₂(g) + NO₂(g) ↔ SO₃(g) + NO(g)

If 0.20 M of SO₂ is initially mixed with 0.30 M NO₂, what is the equilibrium concentration of SO₃? (Quadratic)

• 0.199 M

• 0.301 M

• 0.026 M

• 0.156 M